In manufacturing a semiconductor device and a flat panel display (FPD), a liquid processing apparatus that performs a liquid processing of a substrate such as a semiconductor wafer and a glass substrate is used. There is a known liquid processing apparatus that horizontally supports and rotates a substrate and supplies a processing liquid to the rotating substrate.
The liquid processing apparatus rotates a substrate such that the processing liquid supplied onto the substrate is expanded outward to form a liquid film and the processing liquid is swept away toward outside the substrate. The processing liquid which is swept away by centrifugal force from the rotating substrate is recovered in a cup.
However, when the processing liquid is supplied to the surface of the substrate while the substrate is being rotated, mist or steam of the processing liquid is dispersed onto an upper side of the substrate. The dispersed mist or steam is attached to the substrate again, which causes the occurrence of particles on the substrate.
Therefore, a liquid processing apparatus, which forms air flow toward a cup from an upper side of a substrate by exhausting the liquid inside of the cup to prevent mist or steam from occurring at the upper side of the substrate, has been developed. See, for example, Japanese Patent Application Laid-Open Nos. 2009-038083 and 2008-066400.
An optimal state of air flow at an upper side of a substrate varies according to each liquid process performed during a substrate liquid processing. For example, a substrate liquid processing includes various processing-liquid supplying processes for supplying processing liquids to a substrate and a drying process for sweeping away the processing liquid from the substrate by centrifugal force by rotating the substrate at a high speed. However, the various processing liquid supplying process and the drying process are different in the optimal state of air flow at an upper side of the substrate.
However, in the configuration of the related art, it is difficult to change a condition in order to optimize a state of air flow at an upper side of a substrate according to each liquid process performed during a liquid processing of substrate.